The present invention relates to a power supply control circuit, and more particularly to a power supply control circuit for supplying working power to a DC pump.
When a certain electric appliance is specified to use an alternating current, it means the electric appliance is limited to indoor use or to the best used outdoors by connecting it to an extension line which is connected to an AC power source. When such electric appliance is to be used at places where it cannot be reached by an extension line, such as in the suburbs or in a car, it simply becomes unusable.
An example of such electric appliance is an AC pump generally used indoors. When a pump is needed at a site where no AC power source is available, the general AC pump is simply useless. For instance, an inflatable massage cushion designed for use in a car can be timely used to massage a driver's back and hips to relieve the driver from the tiredness after a long driving time. However, such massage cushion has to be actuated by a pump. Or, to inflate a big floating article on the beach, such as an inflatable raft, a pump is also required. In view that pumps are frequently needed at many outdoor places, it is necessary to develop a DC pump for convenient outdoor use.
It is known that internal components of a pump mainly include a coil, a magnet, an E-shaped steel plate, a rubber diaphragm, a push rod, etc. In the present invention an alternating current is supplied to the coil, 50 so the pump does not need a bridge-type driving circuit. However, if a direct current is supplied to the coil, a bridge-type driving circuit is needed to actuate the pump.